There is an image forming apparatus which forms a visible image (toner image) on an image carrier. The image forming apparatus has various motors, various electric circuits, and a heater (hereinafter, referred to as a heating component). The heating component of the image forming apparatus shares apart of an image forming operation when a current is applied.
The amount of heat generated from the heating component of the image forming apparatus varies in accordance with an operation load. The amount of heat generated from the heating component of the image forming apparatus in an image forming mode becomes greater than that in a standby mode and a sleep mode of the image forming apparatus. In the image forming mode, the larger the number of continuous prints is, the higher the temperature of the heating component of the image forming apparatus is. Each heating component has an allowable temperature for operating normally. Components other than the heating component of the image forming apparatus also have an allowable temperature based on heat resistance of the components or dimensional stability of the components.
The image forming apparatus has cooling fans in order to use each component within an allowable temperature range. The cooling fans include an air blowing fan which supplies low-temperature air to the inside of the apparatus, and an air discharge fan which discharges heated air from the apparatus. The air blowing fan blows air toward the heating component.
In the image forming apparatus in the related art, the cooling fans are turned on and off in each operation mode. In the sleep mode, all of the cooling fans are stopped. In the standby mode, the cooling fan excluding the air discharge fan is stopped. In the image forming mode, all of the cooling fans are driven. For example, in the image forming mode, a CPU drives the cooling fans even in the temperature environment in which there is room for the allowable temperature when starting an operation or the like. Each of the cooling fans is designed such that the temperature thereof does not exceed the allowable temperature of each component even if the amount of heat generated from each heating component becomes maximum.
For this reason, power consumption is increased due to the rotation of the cooling fans particularly in the image forming mode. Furthermore, noise is increased due to the rotation of the cooling fans.